Should be fine. You'll probably end up with some dead yeast as well. But, the process of washing will remove most of the dead yeast and other trub material. Be sure to make a starter when using it. That way the healthy yeast can get a head start and boost their numbers to give you a higher success rate.

If the primary was crash chilled for 4 or so days, would the yeast still be viable for washing?
Any special techniques for warming to room temperature or the pint jars are from the refrigerator anyway and cool is better?

The yeast is on top of the bottom later. The top layer is "beer" (un-useable), it should be poured off. That leaves a thick layer of trub and hops with the yeast lying on top of that. I usually just use the whole bottom layer, as it will settle out with the rest of the trub in primary.

So if I wait a long time for it all to settle out the, top is just beer and I can dump that. Then I could wash again but this time I wait until 20 minutes and dump the top portion and discard the bottom which is trub. Then when I let this second wash settle for a long period, I poor off the top stuff, and have only yeast at the bottom with very little trub, right?